Method for producing cyclic carboxylic orthoester fluorides and corresponding compounds

ABSTRACT

The invention relates to a process for the preparation of cyclic carboxylic acid orthoester fluorides in which
     a) at least one bis(alkylthio)carbenium salt is reacted with at least one organic compound containing at least two hydroxyl groups in the presence of at least one base,   b) and subsequently, preferably in situ, the resultant thioorthoester is subjected to oxidative fluorodesulfurisation using a fluorinating agent and an oxidant to give the cyclic carboxylic acid orthoester fluoride.

The invention relates to a process for the preparation of cyclic carboxylic acid orthoester fluorides, and to novel cyclic carboxylic acid orthoester fluorides obtainable by the process according to the invention.

Cyclic carboxylic acid orthoester fluorides can be used, in particular, as structural constituents of liquid crystals, pharmaceuticals, crop-protection compositions or as precursors for such products or for the preparation of polymers.

The few processes known hitherto for the preparation of carboxylic acid orthoester fluorides are based either on acid-catalysed replacement of alkoxy or acyloxy functions in orthoester derivatives by fluorine (G. Simchen, “Orthocarbonsäure-Derivate” [Orthocarboxylic Acid Derivatives] in Houben-Weyl: Methoden der Organischen Chemie [Methods of Organic Chemistry], Georg Thieme Verlag, Stuttgart, 1985, pp. 54-63) or on the reaction of diols with perfluoroolefins (Bayliff et al., J. Chem. Soc., Perkin Trans. I, 1987, 763-767). By contrast, no generally applicable process for the preparation of cyclic carboxylic acid orthoester fluorides has been disclosed.

It is therefore an object of the invention to provide a process for the preparation of cyclic carboxylic acid orthoester fluorides which starts from readily accessible starting materials, does not require isolation of intermediates, and gives the products in good yields.

A further object of the invention is to describe novel products obtainable by the process according to the invention and to indicate advantageous uses of these products.

The object is achieved by a process according to claim 1. The sub-claims relate to advantageous variants of this process.

The invention thus relates to a process of the type mentioned at the outset, in which

-   a) at least one bis(alkylthio)carbenium salt is reacted with at     least one organic compound containing at least two hydroxyl groups     in the presence of at least one base, -   b) and subsequently, preferably in situ, the resultant     thioorthoester is subjected to oxidative fluorodesulfurisation using     a fluorinating agent and an oxidant to give the cyclic carboxylic     acid orthoester fluoride.

An advantage of the process according to the invention is the ready accessibility of the bis(alkylthio)carbenium salts and the hydroxyl compounds, in particular the diols, as starting compounds.

Furthermore, the oxidative fluorodesulfurisation is carried out under very mild, slightly basic conditions and is therefore, in contrast to the conventional methods, compatible with a multiplicity of unprotected functional groups, for example a nitrile group.

A further particular advantage of the process according to the invention is that the reaction starting from the carbenium salt and the hydroxyl compound to the product can be carried out in a reaction mixture, i.e. without isolation and purification of the intermediates. The yields that can be achieved here are high with low by-product formation.

The invention furthermore relates to novel cyclic carboxylic acid orthoester fluorides obtainable by the process according to the invention, in particular those according to claims 11 and 12. These compounds can be used as structural constituents of liquid crystals, pharmaceuticals, agrochemicals or polymers. A further area of application is use as chiral component or dopant in liquid-crystal mixtures or polymers. These orthoester fluorides can also be used in the presence of one or more Lewis or Brönstedt acids as 1,1-dialkoxyalkylating agents for the preparation of cyclic ketals or cyclic orthocarboxylic acid esters.

Preferred variants of the process according to the invention are described below.

The process according to the invention is preferably carried out using a bis(alkylthio)carbenium salt of the formula II.

In this formula:

-   R¹ is straight-chain, branched or cyclic alkyl having from 1 to 25     carbon atoms, in which one or more H atoms may be replaced by     halogen, —CN or further optionally substituted alkyl and/or aryl     radicals, and/or in which one or more non-adjacent —CH₂— groups may     be replaced, independently of one another, by —CO—, —O—CO—, —CO—O—,     —O—, —S—, —CH═CH—, —C≡C—, —NH— or —N(CH₃)—, and/or aryl, which may     be monosubstituted or polysubstituted by halogen or straight-chain,     branched and/or cyclic alkyl and/or aryl, and in which one or more     CH groups may be replaced by N or O, -   R² and R³, independently of one another, are straight-chain,     branched or cyclic alkyl having from 1 to 12 carbon atoms, where R²     and R³ may be bridged to one another in such a way that the group -    is a 4- to 8-membered ring, and/or in which one or more H atoms may     be replaced by halogen or further optionally substituted alkyl     and/or aryl radicals, and/or in which one or more non-adjacent —CH₂—     groups may be replaced, independently of one another, by —CO—, —O—,     —S—, —CH═CH—, —C≡C—, —NH— or —N(CH₃)—, and/or aryl, which may be     monosubstituted or polysubstituted by halogen or straight-chain,     branched and/or cyclic alkyl and/or aryl, and -   Y⁻ is a non-coordinating or weakly coordinating anion, -   R² and R³ are preferably bridged to one another in such a way that     the -    group is in the form of a 5- to 7-membered ring -    in which R⁴ and R⁵ are H or an optionally substituted alkyl or     alkenyl group having from 1 to 6 carbon atoms, where the group -    may form a cycloalkyl or aryl group, and -   m is 2, 3 or 4.

The process according to the invention is preferably carried out using an organic compound containing at least two hydroxyl groups of the formula III

In this formula:

-   W is a straight-chain, branched or cyclic alkylene group having 2 or     more carbon atoms, in which one or more H atoms may be replaced by     halogen or further optionally substituted alkyl and/or aryl     radicals, and/or in which one or more non-adjacent —CH₂— groups may     be replaced, independently of one another, by —CO—, —O—, —S—,     —CH═CH—, —C≡C—, —NH— or —N(CH₃)—, and/or an arylene group, which may     be monosubstituted or polysubstituted by halogen or straight-chain,     branched and/or cyclic alkyl and/or aryl, and in which one or more     CH groups may be replaced by N or O.

The reaction of a bis(alkylthio)carbenium salt of the formula II with an organic compound containing at least two hydroxyl groups of the formula III gives, in accordance with the invention, a cyclic carboxylic acid orthoester fluoride of the formula I

in which R¹ and W are as defined above.

Preferred hydroxyl compounds of the formula III are those which, when employed in the process according to the invention, are capable of forming cyclic carboxylic acid orthoester fluorides, in particular having 5, 6, 7 or 8 atoms in the orthoester ring. To this end, the group W in the compound of the formula III preferably has, between the two hydroxyl groups, a chain length of 2, 3, 4 or 5 atoms, which may be part of a straight-chain, branched or cyclic aliphatic, aromatic or heteroaromatic group.

The organic compound containing at least two hydroxyl groups is preferably an alkanediol, an aromatic or heteroaromatic dihydroxyl compound, in particular 1,2-dihydroxybenzene, 2,2′-dihydroxy-1,1′-biphenyl, 2,2′-dihydroxy-1,1′-binaphthyl, 7,7′-dihydroxy-1,1′-binaphthyl or 8,8′-dihydroxy-1,1′-binaphthyl, or a hydroxyalkylphenol, in particular salicyl alcohol, which may be substituted by one or more halogen atoms and/or alkyl groups. Preferred alkanediols are ethane-1,2-diol, propane-1,3-diol or 2,2-dimethylpropane-1,3-diol, which may also be monosubstituted or polysubstituted by fluorine and/or chlorine. Preferred halogenated alkanediols are HOCH₂CF₂CH₂OH, HOCH₂CF₂CF₂CH₂OH, HOCH₂CF(CF₃)CH₂OH, HOCH₂C(CF₃)₂CH₂OH, HOCH₂CHFCH₂OH or HOCH₂CCl₂CH₂OH.

In the bis(alkylthio)carbenium salt of the formula II, Y⁻ is preferably a halide, tetrafluoroborate, hexafluorophosphate, perchlorate or alkyl- or arylcarboxylate or alkyl- or arylsulfonate anion, where one, a number or all of the H atoms in the alkyl or aryl groups may be substituted by fluorine or chlorine.

The oxidants used may be conventional oxidants. The oxidant employed is preferably a compound which liberates halonium equivalents. Examples of oxidants are N-chlorosuccinimide, N-bromosuccinimide, N-iodosuccinimide, dibromoisocyanuric acid, 1,3-dibromo-5,5-dimethylhydantoin, chlorine and bromine. Particular preference is given to bromine, since the bromides formed can easily be separated off. Likewise suitable are SO₂Cl₂, SO₂ClF, chloramine-T, nitrosonium and nitronium salts, for example NO⁺BF₄ ⁻. The nitrosonium and nitronium salts may, if desired, also be prepared in situ from suitable precursors, for example from inorganic or organic nitrites and/or nitrates.

The fluorinating agents employed may be conventional fluorinating agents. The fluorinating agent is particularly preferably selected from the group formed by hydrogen fluoride, aliphatic and aromatic amine/hydrogen fluoride complexes, in particular selected from the group formed by pyridine, triethylamine, melamine and polyvinylpyridine/hydrogen fluoride complexes.

When carrying out the process according to the invention, the bis(alkylthio)carbenium salt is preferably employed in a molar ratio of less than or equal to 2:1, in particular less than or equal to 1.7:1, particularly preferably less than or equal to 1.3:1, very particularly preferably less than or equal to 1:1, to the organic compound containing at least two hydroxyl groups. The use of the carbenium salt in an approximately equimolar or sub-stoichiometric amount with respect to the hydroxyl compound generally results in formation of less by-products. Thus, at molar ratios in the range greater than or equal to 2:1, compounds containing one or two CF₂O bridges can form through addition of in each case one bis(alkylthio)carbenium ion onto a hydroxyl group via dithioorthoesters as intermediates and subsequent fluorodesulfurisation.

An example of the way the process according to the invention is carried out is indicated below. A solution of the hydroxyl compound and at least one base is added to a solution of the bis(alkylthio)carbenium salt, preferably at a temperature in the range from −100 to +50° C. Advantageously suitable bases for this purpose are organic nitrogen bases, in particular tertiary aliphatic and/or aromatic amines, such as, for example, triethylamine, pyridine or pyridine derivatives. The base is advantageously employed in a molar ratio of from 1:1 to 2:1, based on the hydroxyl compound. Suitable solvents are, in particular, polar solvents or solvent mixtures, for example ethers or haloalkanes, such as diethyl ether, tetrahydrofuran, dichloromethane and/or trichloromethane.

Intermediates, such as thioorthoesters, formed by reaction of the bis(alkylthio)carbenium salts with the hydroxyl compounds are generally not isolated, but are subjected directly to oxidative desulfurisation in the reaction mixture to give the cyclic carboxylic acid orthoester fluoride.

To this end, the fluorinating agent and the oxidant are added to the reaction mixture. The temperature of the mixture is advantageously then increased, for example to from −20° C. to 50° C. The cyclic carboxylic acid orthoester fluoride can be obtained from the reaction mixture by methods familiar to the person skilled in the art, for example by recrystallisation and/or chromatography.

The bis(alkylthio)carbenium salts as starting materials in the process according to the invention are readily accessible by known methods, for example by condensation of carboxylic acids or activated carboxylic acid derivatives with dithiols. These are particularly advantageously obtained by addition of an acid onto a ketene dithioketal. Thus, the bis(alkylthio)carbenium salt of the formula II is obtainable by addition of an acid HY, in which Y is as defined above, onto a ketene dithioketal of the formula IV

In the formula IV, R² and R³ are as defined above, and R and R′ have, independently of one another, one of the meanings indicated above for R¹, including H, in such a way that the group

has the same meaning as R¹.

The acid is employed in an approximately equimolar amount, based on the ketene dithioketal units to be reacted. The reaction with the acid HY is advantageously carried out at a temperature in the range of from −80 to +30° C. in an inert polar solvent or solvent mixture, as already mentioned above by way of example. Particularly preferred acids HY here are trifluoromethanesulfonic acid and a tetrafluoroboric acid/diethyl ether complex.

An advantage of this process variant starting from ketene dithioketal is the fact that the addition of acid onto the ketene dithioketals can be carried out even under very mild conditions. This gives access to bis(alkylthio)carbenium salts which contain sensitive functional groups, such as esters, nitriles or ketals.

Furthermore, this variant has the advantage that the formation of the bis(alkylthio)carbenium salt by addition of the acid onto the ketene dithioketal is reversible. On use of 4-substituted cyclohexylidene ketene dithioketals, the trans-substituted cyclohexane derivatives of the bis(alkylthio)carbenium salt, which are more thermodynamically favourable compared with the cis-configuration, and thus trans-substituted cyclohexane compounds containing a carboxylic acid orthoester fluoride function can therefore be obtained with very high selectivity.

For equilibration to give the thermodynamically more favourable isomer, it is therefore advantageous to stir the reaction mixture comprising ketene dithioketal, acid and corresponding carbenium salt for an extended time, in particular for from 15 minutes to 6 hours or even longer, at a temperature of from −80 to +50° C., in particular from −30 to +50° C.

The synthesis steps following the reaction of the ketene dithioketal are preferably carried out in situ, i.e. using the reaction mixture from the first reaction and thus without isolation of the carbenium salt.

According to a further process variant, the ketene dithioketal is obtained from a carbonyl compound. In order to obtain a ketene dithioketal of the formula IV, use is made of a carbonyl compound of the formula V

in which R and R′ are as defined above.

R and R′ may be linked to one another with formation of a cyclic group. Examples thereof are cyclohexanone and 4-substituted cyclohexanone derivatives.

The carbonyl compound may also have two or more carbonyl functions. Examples thereof are cyclohexane-1,4-dione and compounds containing 2 cyclohexanone groups. According to a first sub-variant, all carbonyl functions can be converted in accordance with the invention into ketene dithioketal functions and further into carboxylic acid orthoester fluoride functions. According to a second sub-variant, one or more carbonyl functions can be protected as the ketal before the reaction, with at least one carbonyl group remaining unprotected for conversion into the ketene dithioketal. The carboxylic acid orthoester fluorides accessible therefrom in accordance with the invention have one or more carbonyl functions, optionally protected as the ketal, in addition to the orthoester fluoride group. The free carbonyl function can advantageously be used to build up an optionally substituted alkyl, alkenyl or alkoxy group.

The ketene dithioketals are accessible in a simple manner and in high yields from the carbonyl compounds by processes known per se. Mention may be made here by way of example of D. J. Ager, Org. React. 1990, 38, 1-223, in particular pages 63, 95 and 96. It is advantageous that the carbonyl compounds may additionally contain acid-labile substituents, for example ketals or acetals, for masking of carbonyl functions. Furthermore, the ketene thioketals obtainable therefrom can generally be purified well due to their good crystallisation properties, but nevertheless have good solubility in the usual organic solvents.

A process which is preferred here is the reaction of a carbonyl compound with a 2-silyl-1,3-dithiane, which may be substituted. Particular preference is given here to the use of 2-trimethylsilyl-1,3-dithiane. The reaction is preferably carried out in the presence of a deprotonating compound, such as alkyllithium, for example n-butyllithium. An advantageous range for the reaction temperature is from −130 to 0° C. Suitable solvents are the solvents or mixtures indicated above.

Starting from the carbonyl compound of the formula V via the ketene dithioketal of the formula IV and the bis(alkylthio)carbenium salt of the formula II′ obtainable by the addition reaction of the acid HY, the cyclic carboxylic acid orthoester fluoride of the formula I′ can be prepared in accordance with the invention by reaction with the hydroxyl compound of the formula III and subsequent fluorodesulfurisation, as indicated in reaction scheme 1.

The formulae I′ and II ′ are identical with the formulae I and II respectively in the case where the group

has the same meaning as R¹.

The entire conversion of the carbonyl compound of the formula V into the cyclic carboxylic acid orthoester fluoride of the formula I′ is particularly preferably carried out as a so-called one-pot process, i.e. without isolation and purification of intermediates.

The present invention likewise relates to the cyclic carboxylic acid orthoester fluorides obtainable by the process according to the invention, in particular those of the formula I

in which R¹ and W are as defined above.

The meaning of the formula I includes all isotopes of the chemical elements bound in the compounds of the formula I. If compounds of the formula I have one or more chiral centres, the formula I also covers enantiomerically pure and enriched forms in addition to the racemates. In enantiomerically pure or enriched form, the compounds of the formula I are also suitable as chiral dopants and in general for achieving chiral mesophases.

The radical R¹ preferably has the formula Ia

in which

-   R^(a) is H, halogen, —CN, —NCS, —SF₅ or alkyl having from 1 to 12     carbon atoms, in which, in addition, one or two non-adjacent —CH₂—     groups may be replaced by —O—, —S—, —CO—, —O—CO—, —CO—O—, -E- and/or     —C≡C—, and/or in which, in addition, one or more H atoms may be     replaced by halogen and/or —CN, -   E is CR⁴═CR⁵ or CHR⁴—CHR⁵, -   R⁴ and R⁵ are each, independently of one another, H, alkyl having     1-6 carbon atoms, F, Cl, Br, CF₃ or CN, -   Z is —O—CO—, —CO—O—, —C₂H₄—, —CH₂—CF₂—, —CF₂—CH₂—, —CF₂—CF₂—,     —(CF₂)₃—, —(CF₂)₄—, —CH₂—O—, —CF₂—O—, —O—CH₂—, —O—CF₂—, —CH═CH—,     —CF═CH—, —CH═CF—, —CF═CF—, —C≡C— or a single bond, -   A is 1,4-phenylene, in which one or more CH groups may be replaced     by N, 1,4-cyclohexylene, in which one or two non-adjacent CH₂ groups     may be replaced by O and/or S, 1,4-cyclo-hexenylene,     1,4-bicyclo[2.2.2]octylene, piperidine-1,4-diyl,     naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or     1,2,3,4-tetrahydronaphthalene-2,6-diyl, where one or more H atoms in     these groups may be substituted by halogen, —CN and/or optionally     mono- or polyhalogenated alkyl having from 1 to 6 carbon atoms, and -   r is 0, 1, 2, 3 or 4, where groups A and/or Z which occur more than     once may have identical or different meanings. -   r is preferably greater than or equal to 1, in particular 1, 2 or 3.

Particularly preferred meanings of A are 1,4-phenylene, which may be monosubstituted, disubstituted or trisubstituted by fluorine, trans-1,4-cyclohexylene and 1,3-dioxane-2,5-diyl, for which, for reasons of simplicity, the abbreviations Phe, Cyc and Dio respectively are used below.

The term 1,3-dioxane-2,5-diyl in each case covers the two positional isomers

and

The following radicals R¹ of the sub-formulae Ia.1 to Ia.60 are preferred:

R^(a)- Ia.1 R^(a)-Cyc- Ia.2 R^(a)-Phe- Ia.3 R^(a)-Dio- Ia.4 R^(a)-Cyc-Cyc- Ia.5 R^(a)-Cyc-Phe- Ia.6 R^(a)-Cyc-Dio- Ia.7 R^(a)-Phe-Cyc- Ia.8 R^(a)-Phe-Phe- Ia.9 R^(a)-Phe-Dio- Ia.10 R^(a)-Dio-Cyc- Ia.11 R^(a)-Dio-Phe- Ia.12 R^(a)-Cyc-Z-Cyc- Ia.13 R^(a)-Cyc-Z-Phe- Ia.14 R^(a)-Cyc-Z-Dio- Ia.15 R^(a)-Phe-Z-Cyc- Ia.16 R^(a)-Phe-Z-Phe- Ia.17 R^(a)-Phe-Z-Dio- Ia.18 R^(a)-Dio-Z-Cyc- Ia.19 R^(a)-Dio-Z-Phe- Ia.20 R^(a)-Cyc-Cyc-Cyc- Ia.21 R^(a)-Cyc-Cyc-Phe- Ia.22 R^(a)-Cyc-Cyc-Dio- Ia.23 R^(a)-Cyc-Phe-Cyc- Ia.24 R^(a)-Cyc-Phe-Phe- Ia.25 R^(a)-Cyc-Phe-Dio- Ia.26 R^(a)-Cyc-Dio-Cyc- Ia.27 R^(a)-Cyc-Dio-Phe- Ia.28 R^(a)-Phe-Cyc-Cyc- Ia.29 R^(a)-Phe-Cyc-Phe- Ia.30 R^(a)-Phe-Cyc-Dio- Ia.31 R^(a)-Phe-Phe-Cyc- Ia.32 R^(a)-Phe-Phe-Phe- Ia.33 R^(a)-Phe-Phe-Dio- Ia.34 R^(a)-Phe-Dio-Cyc- Ia.35 R^(a)-Phe-Dio-Phe- Ia.36 R^(a)-Dio-Cyc-Cyc- Ia.37 R^(a)-Dio-Cyc-Phe- Ia.38 R^(a)-Dio-Phe-Cyc- Ia.39 R^(a)-Dio-Phe-Phe- Ia.40 R^(a)-Cyc-Z-Cyc-Z-Cyc- Ia.41 R^(a)-Cyc-Z-Cyc-Z-Phe- Ia.42 R^(a)-Cyc-Z-Cyc-Z-Dio- Ia.43 R^(a)-Cyc-Z-Phe-Z-Cyc- Ia.44 R^(a)-Cyc-Z-Phe-Z-Phe- Ia.45 R^(a)-Cyc-Z-Phe-Z-Dio- Ia.46 R^(a)-Cyc-Z-Dio-Z-Cyc- Ia.47 R^(a)-Cyc-Z-Dio-Z-Phe- Ia.48 R^(a)-Phe-Z-Cyc-Z-Cyc- Ia.49 R^(a)-Phe-Z-Cyc-Z-Phe- Ia.50 R^(a)-Phe-Z-Cyc-Z-Dio- Ia.51 R^(a)-Phe-Z-Phe-Z-Cyc- Ia.52 R^(a)-Phe-Z-Phe-Z-Phe- Ia.53 R^(a)-Phe-Z-Phe-Z-Dio- Ia.54 R^(a)-Phe-Z-Dio-Z-Cyc- Ia.55 R^(a)-Phe-Z-Dio-Z-Phe- Ia.56 R^(a)-Dio-Z-Cyc-Z-Cyc- Ia.57 R^(a)-Dio-Z-Cyc-Z-Phe- Ia.58 R^(a)-Dio-Z-Phe-Z-Cyc- Ia.59 R^(a)-Dio-Z-Phe-Z-Phe- Ia.60

Very particularly preferred meanings of R^(a) are F, Cl, CN or alkyl or alkoxy having from 1 to 8 carbon atoms or alkenyl or alkenyloxy having from 2 to 8 carbon atoms, where the alkyl, alkoxy, alkenyl or alkenyloxy radicals may also be mono- to polyhalogenated, in particular fluorinated.

Preferred meanings of Z are —O—CO—, —CO—O—, —C₂H₄—, —CF₂—CF₂—, —CH₂—O—, —CF₂—O—, —O—CH₂—, —O—CF₂—, —CH═CH—, —C≡C— or a single bond.

The following groups W of the sub-formulae I.2a to I.2h are preferred:

in which * indicates the bond to the orthoester fluoride group, and R^(a) has the stated meaning and is preferably H, fluorine, chlorine, CN or optionally fluorinated and/or chlorinated alkyl having from 1 to 6 carbon atoms, and where the radicals R^(a) which occur more than once may have identical or different meanings.

Particularly preferred meanings of the sub-formula I.2b are therefore

In the case of the meaning alkyl in the groups or substituents indicated above or below, in particular in R, R′, R^(a), R¹, R², R³, R⁴ and/or R⁵, the alkyl radical may be linear or branched. It preferably has 1, 2, 3, 4, 5, 6, 7 or 8 carbon atoms. It is preferably linear and is therefore in particular methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. A branched alkyl radical may be chiral or achiral. Preferred chiral alkyl radicals are 2-butyl (=1-methylpropyl), 2-methylbutyl, 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl, 2-propylpentyl and 2-octyl. Preferred achiral alkyl radicals are isopropyl, isobutyl (=methylpropyl) and isopentyl (=3-methylbutyl). The alkyl radicals may be substituted in the manner indicated.

In the case of the meaning alkoxy in the groups or substituents indicated above or below, in particular in R^(a), the alkoxy radical may be linear or branched. It is preferably linear and has 1, 2, 3, 4, 5, 6, 7 or 8 carbon atoms and is therefore in particular methoxy, ethoxy, propoxy, butoxy, pentoxy, hexyloxy, heptyloxy or octyloxy, furthermore nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy or tetradecyloxy.

In the case of the meaning alkenyl in the groups or substituents indicated above or below, in particular in R^(a), the alkenyl radical may be straight-chain or branched. It is preferably straight-chain and has from 2 to 8 carbon atoms. Accordingly, it is in particular vinyl, prop-1- or -2-enyl, but-1-, -2- or -3-enyl, pent-1-, -2-, -3- or -4-enyl, hex-1-, -2-, -3-, -4- or -5-enyl, hept-1-, -2-, -3-, -4-, -5- or -6-enyl, or oct-1-, -2-, -3-, -4-, -5-, -6- or -7-enyl.

In the case of the meaning alkenyloxy in the groups or substituents indicated above or below, in particular in R^(a), the alkenyloxy radical may be straight-chain or branched. It is preferably straight-chain and accordingly is in particular vinyloxy, prop-1- or -2-enyloxy, but-1-, -2- or -3-enyloxy, pent-1-, -2-, -3- or -4-enyloxy, hex-1-, -2-, -3-, -4- or -5-enyloxy, hept-1-, -2-, -3-, -4-, -5- or -6-enyloxy, or oct-1-, -2-, -3-, -4-, -5-, -6- or -7-enyloxy.

The following working examples are intended to illustrate the invention without limiting it. Above and below, percentages are percent by weight. All temperatures are indicated in degrees Celsius. The abbreviation DBH is used for 1,3-dibromo-5,5-dimethylhydantoin.

WORKING EXAMPLES Example 1

53.1 mmol of the thioacetal 10 are dissolved in 70 ml of dichloromethane, 53.1 mmol of trifluoromethanesulfonic acid 11 are slowly added with ice cooling, and the mixture is stirred for 30 minutes. The batch is subsequently cooled to −70° C., and a solution of 64.9 mmol of triethylamine and 23.9 mmol of (−)-S-1,1′-bi(2-naphthol) 12 in 50 ml of dichloromethane is added dropwise over the course of 15 minutes. After a further 45 minutes, 265.5 mmol of triethylamine trishydrofluoride are added slowly, and a suspension of 265.5 mmol of DBH in 120 ml of dichloromethane is then added in portions over the course of 60 minutes. The batch is stirred for a further 90 minutes and warmed to −20° C., and the orange suspension is carefully added to an ice-cold mixture of 1 l of approximately 1M sodium hydroxide solution and 100 ml of sodium hydrogensulfite solution. The aqueous phase is separated off and extracted three times with dichloromethane, and the combined organic phases are subjected to conventional work-up.

The product has a melting point of about 138° C. Mass-spectrometric and NMR analysis show the expected signals.

Example 2

37.0 mmol of the thioacetal 20 are dissolved in 50 ml of dichloromethane, and 37.0 mmol of trifluoromethanesulfonic acid 21 are slowly added with ice cooling. After 40 minutes, the cooling is removed, and the yellow solution is stirred at 20° C. for a further 50 minutes. The batch is subsequently cooled to −70° C., and a solution of 37.0 mmol of triethylamine and 16.6 mmol of (−)-S-1,1′-bi(2-naphthol) 22 in 30 ml of dichloromethane is added dropwise. After 90 minutes, 155 mmol of triethylamine trishydrofluoride are slowly added, and a suspension of 184.8 mmol of DBH in 80 ml of dichloromethane is then added in portions over the course of 45 minutes. After 60 minutes, the batch is allowed to warm to −20° C., and the orange suspension is carefully added to an ice-cold mixture of 1 l of approximately 1M sodium hydroxide solution and 100 ml of sodium hydrogensulfite solution. The aqueous phase is separated off and extracted three times with pentane, and the combined organic phases are subjected to conventional work-up. The product has a melting point of about 143° C. Mass-spectrometric and NMR analysis give the expected signals.

Example 3

76.8 mmol of the dithianylium triflate 30 are introduced into 300 ml of dichloromethane, and a solution of 34.9 mmol of R-(+)-1,1′-bi(2-naphthol) 31 and 38.4 mmol of triethylamine in 50 ml of dichloromethane is added dropwise at −65° C. The mixture is stirred for a further 90 minutes, triethylamine trishydrofluoride (0.38 mol) is slowly added, and a suspension of 0.38 mol of DBH in 150 ml of dichloromethane is then added in portions over the course of 40 minutes. After 60 minutes, the batch is allowed to warm to −20° C., and the orange suspension is carefully added to an ice-cold mixture of 1.5 l of 1M sodium hydroxide solution and 150 ml of sodium hydrogensulfite solution. The aqueous phase is separated off and extracted three times with dichloromethane, and the combined organic phases are subjected to conventional work-up. Mass-spectrometric and NMR analysis give the expected signals.

Example 4

34.9 mmol of S-(−)-1,1′-bi(2-naphthol) 41 are introduced into 120 ml of dichloromethane. 76.8 mmol of triethylamine are added, and a solution of 34.9 mmol of the dithianylium triflate 40 in 80 ml of dichloromethane are added dropwise over the course of 1 hour at −65° C. The mixture is stirred for a further 1 hour, 0.15 mol of triethylamine trishydrofluoride is added slowly, and a suspension of 0.105 mol of DBH in 50 ml of dichloromethane is then added in portions over the course of 90 minutes. After 60 minutes, the batch is allowed to warm to −20° C., and the orange suspension is carefully added to an ice-cold mixture of 500 ml of 1M sodium hydroxide solution and 50 ml of sodium hydrogensulfite solution (pH=7). The aqueous phase is separated off and extracted three times with dichloromethane, and the combined organic phases are subjected to conventional work-up. The product has a melting point of about 228° C. Mass-spectrometric and NMR analysis give the expected signals.

The following compounds, defined by the group W and the radical R¹ in the formula I, are obtained analogously to the above working examples:

No. W R¹  50 1,1′-Binaphthalene-2,2′-diyl —C₃H₇  51 1,1′-Binaphthalene-2,2′-diyl —C₄H₉  52 1,1′-Binaphthalene-2,2′-diyl —C₆H₁₃  53 1,1′-Binaphthalene-2,2′-diyl

 54 1,1′-Binaphthalene-2,2′-diyl

 55 1,1′-Binaphthalene-2,2′-diyl

 56 1,1′-Binaphthalene-2,2′-diyl

 57 1,1′-Binaphthalene-2,2′-diyl

 58 1,1′-Binaphthalene-2,2′-diyl

 59 1,1′-Binaphthalene-2,2′-diyl

 60 1,1′-Binaphthalene-2,2′-diyl

 61 1,1′-Binaphthalene-2,2′-diyl

 62 1,1′-Binaphthalene-2,2′-diyl

 63 1,1′-Binaphthalene-2,2′-diyl

 64 1,1′-Binaphthalene-2,2′-diyl

 65 1,1′-Binaphthalene-2,2′-diyl

 66 1,1′-Binaphthalene-2,2′-diyl

 67 1,1′-Binaphthalene-2,2′-diyl

 68 1,1′-Binaphthalene-2,2′-diyl

 69 1,1′-Binaphthalene-2,2′-diyl

 70 1,1′-Binaphthalene-2,2′-diyl

 71 1,1′-Binaphthalene-2,2′-diyl

 72 1,1′-Binaphthalene-2,2′-diyl

 73 1,1′-Binaphthalene-2,2′-diyl

 74 1,1′-Binaphthalene-2,2′-diyl

 75 1,1′-Binaphthalene-2,2′-diyl

 76 1,1′-Binaphthalene-2,2′-diyl

 77 1,1′-Binaphthalene-2,2′-diyl

 78 1,1′-Binaphthalene-2,2′-diyl

 79 1,1′-Binaphthalene-2,2′-diyl

 80 1,1′-Binaphthalene-2,2′-diyl

 81 1,1′-Binaphthalene-2,2′-diyl

 82 1,1′-Binaphthalene-2,2′-diyl

 83 1,1′-Binaphthalene-2,2′-diyl

 84 1,1′-Binaphthalene-2,2′-diyl

 85 1,1′-Binaphthalene-2,2′-diyl

 86 1,1′-Binaphthalene-7,7′-diyl —C₃H₇  87 1,1′-Binaphthalene-7,7′-diyl —C₅H₁₁  88 1,1′-Binaphthalene-7,7′-diyl

 89 1,1′-Binaphthalene-7,7′-diyl

 90 1,1′-Binaphthalene-7,7′-diyl

 91 1,1′-Binaphthalene-7,7′-diyl

 92 1,1′-Binaphthalene-7,7′-diyl

 93 1,1′-Binaphthalene-7,7′-diyl

 94 1,1′-Binaphthalene-7,7′-diyl

 95 1,1′-Binaphthalene-7,7′-diyl

 96 1,1′-Binaphthalene-7,7′-diyl

 97 1,1′-Binaphthalene-7,7′-diyl

 98 1,1′-Binaphthalene-7,7′-diyl

 99 1,1′-Binaphthalene-7,7′-diyl

100 1,1′-Binaphthalene-7,7′-diyl

101 1,1′-Binaphthalene-7,7′-diyl

102 1,1′-Binaphthalene-7,7′-diyl

103 1,1′-Binaphthalene-8,8′-diyl —C₄H₉ 104 1,1′-Binaphthalene-8,8′-diyl —C₇H₁₅ 105 1,1′-Binaphthalene-8,8′-diyl

106 1,1′-Binaphthalene-8,8′-diyl

107 1,1′-Binaphthalene-8,8′-diyl

108 1,1′-Binaphthalene-8,8′-diyl

109 1,1′-Binaphthalene-8,8′-diyl

110 1,1′-Binaphthalene-8,8′-diyl

111 1,1′-Binaphthalene-8,8′-diyl

112 1,1′-Binaphthalene-8,8′-diyl

113 1,1′-Binaphthalene-8,8′-diyl

114 1,1′-Binaphthalene-8,8′-diyl

115 1,1′-Binaphthalene-8,8′-diyl

116 1,1′-Binaphthalene-8,8′-diyl

117 1,1′-Binaphthalene-8,8′-diyl

118 1,1′-Binaphthalene-8,8′-diyl

119 1,1′-Binaphthalene-8,8′-diyl

120 1,2-Phenylene —C₅H₁₁ 121 1,2-Phenylene

122 1,2-Phenylene

123 1,2-Phenylene

124 1,2-Phenylene

125 1,2-Phenylene

126 1,2-Phenylene

127 1,2-Phenylene

128 1,2-Phenylene

129 1,2-Phenylene

130 1,2-Phenylene

131 1,2-Phenylene

132 1,2-Phenylene

133 1,2-Phenylene

134 1,2-Phenylene

135 1,2-Phenylene

136 1,2-Phenylene

137 1,2-Phenylene

138 1,2-Phenylene

139 4-Fluoro-1,2-phenylene

140 4-Fluoro-1,2-phenylene

141 4-Fluoro-1,2-phenylene

142 4-Fluoro-1,2-phenylene

143 4-Fluoro-1,2-phenylene

144 1,1′-Biphenyl-2,2′-diyl —C₅H₁₁ 145 1,1′-Biphenyl-2,2′-diyl

146 1,1′-Biphenyl-2,2′-diyl

147 1,1′-Biphenyl-2,2′-diyl

148 1,1′-Biphenyl-2,2′-diyl

149 1,1′-Biphenyl-2,2′-diyl

150 1,1′-Biphenyl-2,2′-diyl

151 1,1′-Biphenyl-2,2′-diyl

152 1,1′-Biphenyl-2,2′-diyl

153 1,1′-Biphenyl-2,2′-diyl

154 1,1′-Biphenyl-2,2′-diyl

155 1,1′-Biphenyl-2,2′-diyl

156 1,1′-Biphenyl-2,2′-diyl

157 1-Methylbenzene-1,2-diyl —C₅H₁₁ 158 1-Methylbenzene-1,2-diyl

159 1-Methylbenzene-1,2-diyl

160 1-Methylbenzene-1,2-diyl

161 1-Methylbenzene-1,2-diyl

162 1-Methylbenzene-1,2-diyl

163 1-Methylbenzene-1,2-diyl

164 1-Methylbenzene-1,2-diyl

165 1-Methylbenzene-1,2-diyl

166 1-Methylbenzene-1,2-diyl

167 1-Methylbenzene-1,2-diyl

168 1-Methylbenzene-1,2-diyl

169 1-Methylbenzene-1,2-diyl 

1. A process for preparing a cyclic carboxylic acid orthoester fluoride, comprising reacting: a) at least one bis(alkylthio)carbenium salt with at least one organic compound containing at least two hydroxyl groups in the presence of at least one base, b) and subsequently, subjecting to oxidative fluoride sulfurisation using a fluorinating agent and an oxidant the resultant thioorthoester to give the cyclic carboxylic acid orthoester fluoride.
 2. A process according to claim 1, wherein a bis(alkylthio)carbenium salt is of the formula II

wherein R¹ is a straight-chain, branched or cyclic alkyl having from 1-25 carbon atoms, wherein one or more H atoms may be replaced by halogen, —CN or further optionally substituted alkyl and/or aryl radicals, and/or wherein one or more non-adjacent —CH₂— groups may be replaced, independently of one another, by —CO—, —O—CO—, —CO—O—, —O—, —S—, —CH═CH—, —C≡C—, —NH— or —N(CH₃)—, and/or aryl, which may be monosubstituted or polysubstituted by halogen or straight-chain, branched and/or cyclic alkyl and/or aryl, and wherein one or more CH groups may be replaced by N or O, R² and R³, independently of one another, are straight-chain, branched or cyclic alkyl having from 1-12 carbon atoms, where R² and R³ may be bridged to one another in such a way that the group

 is a 4- to 8-membered ring, and/or wherein one or more H atoms may be replaced by halogen or further optionally substituted alkyl and/or aryl radicals, and/or wherein one or more non-adjacent —CH₂— groups may be replaced, independently of one another, by —CO—, —O—, —S—, —CH═CH—, —C≡C—, —NH— or —N(CH₃)—, and/or aryl, which may be monosubstituted or polysubstituted by halogen or straight-chain, branched and/or cyclic alkyl and/or aryl, and Y⁻ is a non-coordinating or weakly coordinating anion, and the organic compound containing at least two hydroxyl groups of the formula III

wherein W is a straight-chain, branched or cyclic alkylene group having 2 or more carbon atoms, wherein one or more H atoms may be replaced by halogen or further optionally substituted alkyl and/or aryl radicals, and/or wherein one or more non-adjacent —CH₂— groups may be replaced, independently of one another, by —CO—, —O—, —S—, —CH═CH—, —C≡C—, —NH— or —N(CH₃)—, and/or an arylene group, which may be monosubstituted or polysubstituted by halogen or straight-chain, branched and/or cyclic alkyl and/or aryl, and wherein one or more CH groups may be replaced by N or O, to give a cyclic carboxylic acid orthoester fluoride of the formula I


3. A process according to claim 1, wherein the oxidative fluorodesulfurisation is in situ.
 4. A process according to claim 2, wherein that the oxidative fluorodesulfurisation is in situ.
 5. A process according to claim 1, wherein the organic compound containing at least two hydroxyl groups is an alkanediol, an aromatic or heteroaromatic dihydroxyl compound or a hydroxyalkylphenol, each of which may be substituted by one or more halogen atoms and/or alkyl groups.
 6. A process according to claim 2, wherein Y ⁻ is a halide, tetrafluoroborate, hexafluorophosphate, perchlorate or alkyl- or arylcarboxylate or alkyl- or arylsulfonate anion, where one, a number or all of the H atoms in the alkyl or aryl groups may be substituted by fluorine or chlorine.
 7. A process according to claim 1, wherein the oxidant is a compound which liberates halonium equivalents.
 8. A process according to claim 1, wherein the fluorinating agent is selected from the group formed by hydrogen fluoride, aliphatic and aromatic amine/hydrogen fluoride complexes, in particular selected from the group formed by pyridine, triethylamine, melamine and polyvinylpyridine/hydrogen fluoride complexes.
 9. A process according to claim 1, wherein the bis(alkylthio)carbenium salt is employed in a molar ratio of less than or equal 2:1, to the organic compound containing at least two hydroxyl groups.
 10. A process according to claim 1, wherein the bis(alkylthio)carbenium salt is obtained by addition of an acid onto a ketene dithioketal.
 11. A process according to claim 2, wherein the bis(alkylthio)carbenium salt is obtained by addition of an acid onto a ketene dithioketal, wherein the bis(alkylthio)carbenium salt of the formula II is obtained by addition of an acid HY, onto a ketene dithioketal of the formula IV

and R and R′, independently of one another, are as defined for R¹, including H, in such a way that the

 group has the same meaning as R¹.
 12. A process according to claim 10, wherein the ketene dithioketal is obtained from a carbonyl compound by reaction with one or more thiol compounds.
 13. A process according to claim 1, wherein the oxidant is dimethyldibromohydantoin, N-chlorosuccinimide, N-bromosuccinimide, N-iodosuccinimide, dibromoisocyanuric acid, chlorine, bromine, SO₂Cl₃, SO₂ClF, a nitrosonium, a nitronium salt, an organic or inorganic nitrite or chloramine-T.
 14. A process according to claim 1, wherein the fluorinating agent is pyridine, triethylamine, melamine, or a polyvinylpyridine/hydrogen fluoride complex.
 15. A process according to claim 1, wherein the bis(alkythio)carbenium salt is employed in a molar ratio of less than or equal to 1.3:1, to the organic compound containing at least two hydroxyl groups. 